Constantinople/Istanbul

Timeline

1. 330Site of Byzantium (Constantinople) · Eastern Roman EmpireConstantine I expanded the ancient city of Byzantium and designated it as the new capital of the Roman Empire, 'New Rome,' controlling the Black Sea and Mediterranean trade routes and laying the pattern of the imperial capital for the next thousand years.
2. 395–1453Constantinople · Byzantine EmpireAs the capital of the Eastern Roman/Byzantine Empire for over a thousand years, the city sustained the imperial center through the Theodosian Walls, Hagia Sophia, and the palace administrative system, and revived multiple times despite Arab sieges, Crusader sackings, and the Latin Empire period.
3. 1453Constantinople · Ottoman EmpireMehmed II led his army to breach the walls, and the Byzantine Empire fell; the city was renamed Istanbul and became the Ottoman capital, Hagia Sophia was converted into a mosque, and the city entered a new phase as the capital of an Islamic empire.
4. 1453–1922Istanbul · IstanbulDuring the reign of Suleiman the Magnificent and others, Topkapı Palace, the Blue Mosque, and the Grand Bazaar were built; the city became an imperial administrative, religious, and commercial hub spanning Europe and Asia, with its population and diverse communities reaching a historical peak.
5. 1923Istanbul · IstanbulAfter the Republic of Turkey moved its capital to Ankara, Istanbul lost its status as imperial capital but remained an economic and cultural center; large-scale urbanization in the 20th century and projects such as the Bosphorus Bridge shaped its modern international metropolis appearance, with Byzantine and Ottoman legacies coexisting.